Method of making brominated indigos



Applicaticn filed ."ficccmhcr n he T iii wiicm may conccwi:

Be it c n that WB; CHARLES J, Swim- SACZUSR cWAnn J. linemen citizens ea-lee, and residen of Midc lend cci didiand, State of IVlicl" digc a Stein 5;" masterini have ed a, new use Elie several bcn'iine Sllxbsilin 'tlicds Of Me; a Lie-is. 1e latter We have 0s, c": which the folic-w produce by allowing inn; iii

i; liminine who act directly on e k explained and the best ncc either with or witlicut ilie pres which we lave contemplated applying that ineit diiwant namely cei-bcn 'te principle no as in distinguish it from e ther Hie reaction lieing ccnducied inven'tic c time of from "50 degrees he 80 de 1121' on the principle of "Elie c ineti-on 0'1 indigo especially grade, under ertmcspiiecic p 1S WhGEE: the 161 bromine substituted pied reaction i-equiies be can f nets are desired has apparently been llleffelin-HTS, the pericd lasing; lc-i mime iegerded as presenting; peculiar vdifiidesired in produce the liig culties. Enrthe-rmore, the liigliesi number fpc-nnis indicated elieve. 'lllie anic cl broin' atoms that have been thus snbbromine eniplcyed will be scniewiiat stituted die benzene nuclei lies nee/n six. ccss (If the tliec" 192d required 0. fc-i In View '1 the reported difiicnlieg in bmdesired siliis'ti'tmicn "product "W" ether die mine-wing indigo L0 cbtein the higher derive; letter Te 11'10110-i310i11 ibeiin-ln'cin z? fives, necessitating the use 0i" particular alumn ilQKEE-lTFGTI'i, iiepie-bmm 0-1 cctc diluent-s 0:? vehicles in Which-I0 carry 0n the indigo, F 01 nodncing the l-OWGT' in" i0 reaction between the original indige and the derivati es just eiinmeiznted en up to blOKQl 3 Well the use c-fi elevated 'leml'YEOIfl inc c excess cc? from 15 3c PGFZZUZFBS c2 presences 0E lOQlZll, c111 per cent 01 bi'cniinc Will be discovery is indeed surprising since We have prcducing 'LllQ, ben n-b n: i

it "cssinle tc directly react midi? indigc,l1his excess sliculd scinewliet .iigii- 75 en bromine at atmospheric na-e3 ei' e. g. per cem,

sure L l temperature 210i, above- 80 The dry indigo with I Tacie. ii Vhere ei' diluent in liquid lJTIOiZ-QIIQQ, is placed .nlained, is einplcyed, the reenameled TEZlCillCll cnninlc ce'riied on in ordinary ifcn in- S'iliITlDg Held in. 39 neied vessels. By the gimp-1e with constant sinliing' at a. 'ieninei P'EC'CEQL e 'iiich is Outlined We have fun om to: de i theinicre been successful in obtaining 5W0 iiiglciec cmi iidig'ces,wliicli so We are i EiOH comnlete, may l aware l e never heretofore been pfcdnced, by analysis. it 01 pi cdncing 35 nai'nel neptmnrom indigo end cccdbrcin 1lVR-l/l7@5 the i'eec i-c-n may indigc', respectively c-c/nteining seven and continued i501 ten 0 tWelY-e eight ms cf bromine attached "0 the ben- Wards. It will lie elec nndeml csd J zene nuclei stopping bile b mmineivicn en ine i Te iii-e ecccinplis-hmen'l; cf the obiec'ts time a. mixture iligllal and icwes fg indicated, the invention, then, ccnsiets of m ne d iivei ives will lee ele' ei d. the seeps heieinefter fully described and "pm-duel; is nci; necessarily containing a quantity of iron balls which grind the indigo at the same time that they keep it and the bromine which is dissolved in the tetrachloride in thorough and constantly changing contact. Such drum will of course be jacketed to permit the temperature to be properly controlled.

In either case the bromine which has not entered into reaction is distilled off or otherwise separated from the mass of indigo derivative, and the latter thereupon treated with a bisulphite solution in order to remove that part of the bromine which is attached elsewhere than to the benzene nuclei. The resulting brominated indigo, whether in paste or powder (i. e. dry) form, presents much the appearance of ordinary indigo paste or powder except that a progressive change in color from the deep blue of pure indigo to a reddish purple is observable in passing from the lower to the higher bromine derivates. In other words, the monobrom and dibrom indigo differ but little to all outward appearance from indi 0, while the octo-brom indigo possesses a eep reddish'purple towards which the intermediate products, e. g. penta-brom, hexa-brom and hepta-brom indigos successively moreiclosely approach.

The constitution of the several brominated indigos, the two higher members of which (now obtained for the first time) -complete the series in so far as substitution in the benzene nuclei is possible, has been found upon analysis to correspond very closely with the theoretical, as indicated by the following table, viz

Mono-brom indigo 23.46 of bromine Di-brom indigo 38.0 Tri-brom indigo 48.0 Tetra-brom indigo 55.3 Penta-brom indigo...- 60.88 Hexa-brom indigo 65.18% Hepta-brom indigo--- 68.71 Octo-brom indigo 71.5

Other modes of applying the principle of our invention may be employed instead of the one explained, change being made as regards the method herein disclosed, provided the steps stated by any of the following claims or the equivalent of such stated steps be employed.

\Ve therefore particularly point out and distinctly claim as our invention 2-- 1. The method of brominating indigo, which consists in reacting directly on the same dry with bromine in amount from 15% to 25% in excess of the theoretical to form the desired substitution product, the reaction being carried on at a temperature of from 7 0 to 80 C. and under atmospheric pressure;

2. The method of brominating indigo, which consists in grinding the same in dry form in a bodybf carbon tetrachloride to which has been. added the requisite amount of bromine, substantially as described.

3. The method of brominating indigo, which consists in reacting directly on the same dry, in the presence of carbon tetrachloride, with bromine in amount from 15 per cent to 25 per cent in excess of the theoretical to form the desired substitution product, the reaction being carried on at a temperature of from 70 to 80 C. and under atmospheric pressure.

Signed by us,th1s 7th day of December,

CHARLES J. S TROSACKER. HOWARD J. RUPRIGHT. 

